Impact wrenches are commonly used to remove work pieces, such as threaded fasteners, from a working material. A motor drives the hammer rotationally by initiating quick pulses of power, either through electrical, pneumatic or other means. The anvil, which is disposed interior of the impact wrench, includes wings that interact with the hammers and transfer the impacting force from the hammers to the work piece. For example, a first wing on the anvil can engage a first hammer, and a second wing spaced axially from the first wing can engage a second hammer. The wings each engage their respective hammer approximately every 360 degrees of rotation.
Current impact wrench anvils include wings with rectangular surfaces, such as that shown in FIG. 7. The anvil 700 of FIG. 7 includes a first wing 705 with a first surface 710, and a second wing 715 with a second surface 720. The two surfaces 710, 720 are rectangular and do not overlap one another in a circumferential or axial direction. In other words, the first and second surfaces 710, 720 are diametrically opposed and axially spaced relative to each other. That is, the first wing 705 is adapted to engage a first hammer, and the second wing 715 is adapted to engage a second hammer. If the wings 705, 715 axially overlapped with one another, the first wing would engage the second hammer, and the second wing would engage the first hammer which would prevent the hammers from rotating relative to the anvil.